Two-sided manhole step

ABSTRACT

A two-sided manhole step. The step includes a first step surface and a second step surface. Lugs extend from ends of the first and second step surfaces. The lugs help to prevent individuals from sliding off the manhole step, regardless of whether the step is installed with the first step surface or second step surface facing upwards.

This application relates to and claims the benefit of U.S. ProvisionalApplication No. 60/488,187, filed Jul. 17, 2003 and entitled “Two-SidedManhole Step”, which is hereby incorporated in its entirety by thisreference.

FIELD OF THE INVENTION

This invention relates to manhole steps and ladders, more specifically,the present invention relates to two-sided manhole steps.

BACKGROUND OF THE INVENTION

Pre-cast concrete manholes are widely used throughout the world toprovide access to storm and sanitary sewer systems and a variety ofother below-ground installations of piping, cables and the like. Forsuch accesses to be used, a ladder or steps must be provided to permitworkers to descend into and climb out of the manhole. A variety ofstructures have been employed to make this possible, includingtemporarily positioning ladders in the manhole and permanently attachingladders or steps to the inside wall of the manhole.

One such step is disclosed in U.S. Pat. No. 4,100,997, which isincorporated herein by reference. U.S. Pat. No. 4,100,997 describes asteel reinforced plastic step that is injection molded of copolymerpolypropylene. Support members that terminate at ends having molded,deformable annular projections are driven into preformed holes in theinside wall of the manhole. The disclosed step of U.S. Pat. No.4,100,997 has an upper flat step surface attached to the two supportmembers. At each end of the flat support surface is an upward projectionmember that projects at approximately 90° from the flat step surface.

Such upward projection members ensure that the manhole step complieswith OSHA Standard No. 1910.27(b)(1)(v), which requires that the “rungsof an individual-rung ladder shall be so designed that the foot cannotslide off the end.” FIG. 1 shows an OSHA suggested design for rungs 8 onindividual-rung ladders installed in concrete 6.

A problem occurs when manhole steps are installed and due to theinstallation process the steps are installed upside down. When stepssuch as the one shown in U.S. Pat. No. 4,100,997 or the one shown inFIG. 1 are installed upside down, they would no longer comply with theOSHA standards.

SUMMARY

Embodiments of the present invention include a two sided step whichincludes a first step surface, a second step surface, at least oneattachment member for securing the step to a structure, first and secondlugs extending substantially perpendicular from ends of the first stepsurface, and third and fourth lugs extending substantially perpendicularfrom ends of the second step surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) illustrates a prior art manhole step.

FIG. 1(b) illustrates a side view of a prior art manhole step of FIG.1(a).

FIG. 2 illustrates a perspective view of an embodiment of the presentinvention.

FIG. 3 illustrates a top view of an embodiment of the present invention.

FIG. 4 illustrates a right side view of an embodiment of the presentinvention.

FIG. 5 illustrates a front view of an embodiment of the presentinvention.

FIG. 6 illustrates a back view of an embodiment of the presentinvention.

DETAILED DESCRIPTION

FIGS. 2-6 illustrate various views of a steel reinforced, molded plasticstep 10 which is molded from plastic material such as polypropylene orother well-known plastic material. The step 10 is integrally formedhaving a step member 12 with a first flat step surface 14 and a secondflat step surface 16 and respective opposed, step support members 18, 20extending substantially perpendicular from the step member 12. The stepsupport members 18, 20 are attachment members for securing the step 10in the wall of a manhole or other desired structure. Various suitableattachment members, in any desired number or configuration, known tothose skilled in the art can be used.

Each end of the step support members is provided with a means 22, 24 forretaining the step 10 in place in tapered holes or bores formed in theconcrete wall of a manhole or other desired structure. Each end can beidentical or similar in construction and can be molded to include aplurality of evenly spaced circular projections which may be smaller orless in diameter from one another such that the means 22, 24 tapertowards distal ends. The operation of the ends is described in moredetail in U.S. Pat. No. 4,100,997. Other means for retaining the step inconcrete known to those skilled in the art can be used.

Both ends of the step member 12 have integrally formed lugs 26, 28, 34and 36 that project outwardly from the first step surface 14 and projectoutwardly from the second step surface 16. As shown in FIGS. 2-6, thelugs extend substantially perpendicular from the first and second stepsurfaces. Ribbing 30, 32, located on the outside of the lugs, reinforcesthe lugs. Other means of reinforcement can be used as are known to thoseskilled in the art.

The lugs 26, 28, 34 and 36 can facilitate prevent a user's foot fromslipping off a side of the step 10.

In the embodiments shown in FIGS. 4-6, the first step surface 14 can beidentical to the second step surface 16. The first step surface 14 hasreflection symmetry with respect to the second step surface 16.

In the embodiments shown in FIGS. 2-6, first and second step surfacesinclude treads 38 and 40 which may provide additional traction for thestep's user. Treads 38 and 40 can be formed in several different designsand shapes as is known to one skilled in the art.

To install the step 10, two tapered openings or bores are first drilledinto a wall of the manhole or other structure using a drill or othersuitable means. In another embodiment, the openings are preformed in thewall. Next, the ends of the step support members are aligned with therespective openings and then hammered in place by a mallet or smallsledge hammer, causing the circular projections to deform and securelyhold the step 10 in the openings. Because the step 10 is symmetric withrespect to its first and second step surfaces and associated lugs, themanhole step of the present invention can be installed with either stepsurface facing upwardly, so that it cannot be installed upside down.

As those skilled in the art will appreciate, the particular embodimentof this invention described above and illustrated in the figures isprovided for explaining the invention, and various alterations may bemade in the structure and materials of the illustrated embodimentwithout departing from the spirit and scope of the invention asdescribed above.

1. A step comprising: (a) a first step surface; (b) a second stepsurface; (c) at least one attachment member for securing the step to astructure; (d) a first lug extending substantially perpendicular from afirst end of the first step surface; (e) a second lug extendingsubstantially perpendicular from a second end of the first step surface;(f) a third lug extending substantially perpendicular from a first endof the second step surface; and (g) a fourth lug extending substantiallyperpendicular from a second end of the second step surface.
 2. The stepof claim 1, further comprising a top side and a bottom side, wherein thetop side is symmetrical to the bottom side.
 3. The step of claim 2,wherein the top side is a reflection of the bottom side.
 4. The step ofclaim 2, wherein the top side comprises the first step surface, thefirst lug, and the second lug; and wherein the bottom side comprises thesecond step surface, the third lug, and the fourth lug.
 5. The step ofclaim 1, wherein the manhole step is molded plastic.
 6. The step ofclaim 5, wherein the manhole step is polypropylene.
 7. The step of claim5, wherein the manhole step is reinforced with steel.
 8. The step ofclaim 1, wherein the first, second, third, and fourth lugs arereinforced.
 9. The step of claim 8, further comprising ribs reinforcingthe first, second, third, and fourth lugs.
 10. The step of claim 9,wherein the ribs extend from outer surfaces of the first, second, third,and fourth lugs.
 11. The step of claim 1, wherein at least portions ofthe first and second step surfaces comprise treads.
 12. The step ofclaim 1, wherein the at least one attachment member comprises two stepsupport members.
 13. The step of claim 12, wherein the two step supportmembers taper towards distal ends; and wherein the distal ends furthercomprise a plurality of projections circumscribing the ends.
 14. Amanhole step, comprising: (a) a first step surface; (b) a second stepsurface; (c) two step support members for securing the manhole step to astructure; wherein the two step support members taper towards distalends; (d) a first lug extending substantially perpendicular from a firstend of the first step surface; (e) a second lug extending substantiallyperpendicular from a second end of the first step surface; (f) a thirdlug extending substantially perpendicular from a first end of the secondstep surface; and (g) a fourth lug extending substantially perpendicularfrom a second end of the second step surface.
 15. The manhole step ofclaim 14, wherein the first, second, third, and fourth lugs arereinforced.
 16. The manhole step of claim 15, further comprising ribsreinforcing the first, second, third, and fourth lugs.
 17. The manholestep of claim 16, wherein the ribs extend from outer surfaces of thefirst, second, third, and fourth lugs.
 18. A manhole step, comprising:(a) a step, comprising: (i) a first step surface; (ii) a second stepsurface; (iii) a first lug extending substantially perpendicular from afirst end of the first step surface; (iv) a second lug extendingsubstantially perpendicular from a second end of the first step surface;(v) a third lug extending substantially perpendicular from a first endof the second step surface; (vi) a fourth lug extending substantiallyperpendicular from a second end of the second step surface; and (vii)wherein the first, second, third and fourth lugs are reinforced by aplurality of ribs; and (b) two step support members extendingsubstantially perpendicular from the step; wherein the two step supportmembers taper towards distal ends; and wherein the distal ends furthercomprise a plurality of projections circumscribing the ends.
 19. Themanhole step of claim 18, further comprising a top side and a bottomside, wherein the top side is symmetrical to the bottom side.
 20. Themanhole step of claim 19, wherein the top side is a reflection of thebottom side.